rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=3ba4/1/0x4000000000000000 softirq=9177/9186 fqs=5
	(t=10500 jiffies g=7805 q=197 ncpus=2)
rcu: rcu_preempt kthread starved for 10490 jiffies! g7805 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27848 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4451 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:107 [inline]
RIP: 0010:lock_acquire+0x16d/0x490 kernel/locking/lockdep.c:5658
Code: 19 02 00 00 41 83 3e 00 0f 85 02 01 00 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 4c 8b b4 24 a0 00 00 00 <fa> 48 c7 c7 e0 12 6c 8a e8 46 7f ad 08 65 ff 05 6f 76 9f 7e 45 31
RSP: 0018:ffffc90000007a40 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 17a4b9d57f664900
RDX: 0000000000000000 RSI: ffffffff8abef900 RDI: ffffffff8abef8c0
RBP: ffffc90000007b48 R08: dffffc0000000000 R09: fffffbfff1bfe1c6
R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: 0000000000000000
R13: 1ffff92000000f54 R14: 0000000000000046 R15: dffffc0000000000
FS:  0000555590b8b500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e363fff CR3: 000000005eaa2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 __lock_task_sighand+0x146/0x2d0 kernel/signal.c:1411
 lock_task_sighand include/linux/sched/signal.h:745 [inline]
 send_sigqueue+0x159/0x600 kernel/signal.c:1979
 posix_timer_event kernel/time/posix-timers.c:360 [inline]
 posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:386
 __run_hrtimer kernel/time/hrtimer.c:1747 [inline]
 __hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1811
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ae 05 49 f7 48 89 df e8 06 cb 49 f7 e8 d1 bd 6c f7 fb bf 01 00 00 00 <e8> 96 43 3d f7 65 8b 05 27 f1 e7 75 85 c0 74 02 5b c3 e8 c4 02 e6
RSP: 0018:ffffc90003537b98 EFLAGS: 00000282
RAX: 17a4b9d57f664900 RBX: ffff8880760f1280 RCX: 17a4b9d57f664900
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: 0000000000000001
RBP: ffff8880760f1518 R08: dffffc0000000000 R09: ffffed100ec1e251
R10: ffffed100ec1e251 R11: 1ffff1100ec1e250 R12: 1ffff1100ec1e2a3
R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x1163/0x1350 kernel/signal.c:2874
 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe64358f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd7bf77f88 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fe6437e5fa8 RCX: 00007fe64358f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe6437e5fac
RBP: 0000000000000000 R08: 000b2f71fc163c5d R09: 000000047bf7827f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe6437e5fac
R13: 00007fe6437e5fa0 R14: 0000000000001da6 R15: 0000000000000004
 </TASK>
CPU: 1 PID: 4450 Comm: syz.1.26 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:215
Code: 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 90 30 7e 0c 48 89 de 5b e9 47 68 4f 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d 64 8f 81 7e 65 8b 15 65 8f 81 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90003507a98 EFLAGS: 00000297
RAX: ffffffff812f4254 RBX: ffff88801a740000 RCX: ffff88801a740000
RDX: 0000000000000000 RSI: 00007ffd17b12280 RDI: 00007fffffffecbc
RBP: ffffc90003507c90 R08: dffffc0000000000 R09: ffffed10034e82b0
R10: ffffed10034e82b0 R11: 1ffff110034e82af R12: dffffc0000000000
R13: ffff88801a741900 R14: 00007ffd17b12280 R15: 00007fffffffecbc
FS:  0000555576a53500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e463fff CR3: 00000000778f1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 _static_cpu_has arch/x86/include/asm/cpufeature.h:180 [inline]
 use_xsave arch/x86/kernel/fpu/internal.h:10 [inline]
 copy_fpstate_to_sigframe+0x184/0xcb0 arch/x86/kernel/fpu/signal.c:209
 get_sigframe arch/x86/kernel/signal.c:297 [inline]
 __setup_rt_frame arch/x86/kernel/signal.c:472 [inline]
 setup_rt_frame arch/x86/kernel/signal.c:784 [inline]
 handle_signal arch/x86/kernel/signal.c:828 [inline]
 arch_do_signal_or_restart+0x622/0x1240 arch/x86/kernel/signal.c:873
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6d1538f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd17b12668 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f6d155e5fa8 RCX: 00007f6d1538f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6d155e5fac
RBP: 0000000000000000 R08: 00023ea1b89fac4e R09: 0000000417b1295f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6d155e5fac
R13: 00007f6d155e5fa0 R14: 0000000000001da6 R15: 0000000000000004
 </TASK>
sched: RT throttling activated